Age-specific changes in the molecular phenotype of patients with moderate-to-severe atopic dermatitis

Predictive factors for responders to upadacitinib treatment in patients with atopic dermatitis

BACKGROUND

Janus kinase 1 inhibitor upadacitinib is therapeutically effective for atopic dermatitis (AD). However, predictive factors for high responders to upadacitinib have not been established in real-world clinical practice.

OBJECTIVES

To identify predictive factors for responders to upadacitinib 15 mg or 30 mg, defined as achievers of investigator's global assessment (IGA) 0/1 with ≥ 2-point improvement from basal IGA.

METHODS

A retrospective study was conducted from August 2021 to July 2023 on 159 AD patients treated with upadacitinib 15 mg and 52 patients with 30 mg. Patients in each group were categorized into responders (achievers of IGA 0/1 at week 12) and non-responders (non-achievers). We compared baseline values of clinical and laboratory parameters between responders and non-responders. Logistic regression analysis was used to detect variables predicting responders. Receiver-operating characteristic curves were used for evaluating prediction capabilities of the variables.

RESULTS

In logistic regression analysis, responders to 15 mg upadacitinib were associated with lower total EASI and higher age whereas responders to 30 mg were associated with lower LDH and lower IgE.

CONCLUSIONS

Lower total EASI and higher age may predict responders to upadacitinib 15 mg while lower IgE and lower LDH may predict responders to 30 mg.

Inflammation and aging-related disease: A transdisciplinary inflammaging framework

Inflammaging, a state of chronic, progressive low-grade inflammation during aging, is associated with several adverse clinical outcomes, including frailty, disability, and death. Chronic inflammation is a hallmark of aging and is linked to the pathogenesis of many aging-related diseases. Anti-inflammatory therapies are also increasingly being studied as potential anti-aging treatments, and clinical trials have shown benefits in selected aging-related diseases. Despite promising advances, significant gaps remain in defining, measuring, treating, and integrating inflammaging into clinical geroscience research. The Clin-STAR Inflammation Research Interest Group was formed by a group of transdisciplinary clinician-scientists with the goal of advancing inflammaging-related clinical research and improving patient-centered care for older adults. Here, we integrate insights from nine medical subspecialties to illustrate the widespread impact of inflammaging on diseases linked to aging, highlighting the extensive opportunities for targeted interventions. We then propose a transdisciplinary approach to enhance understanding and treatment of inflammaging that aims to improve comprehensive care for our aging patients.

Genetic support for the causal association between 91 circulating inflammatory proteins and atopic dermatitis: A two-sample Mendelian randomization trial

BACKGROUND

Atopic dermatitis (AD) is a refractory disease that occurs in clinical practice. One of the most common inflammatory skin diseases, its occurrence and development are related to inflammation. Nevertheless, the precise nature of the relationship between circulating inflammatory proteins and AD remains uncertain.

METHODS

A two-sample MR analysis was performed to determine the causal relationship between the expression of 91 circulating inflammatory proteins and AD by using genome-wide association study (GWAS) summary statistics data from the FinnGen consortia. The robustness of the MR results was assessed by means of sensitivity analysis.

RESULTS

The causal relationship between the expression of nine specific circulating inflammatory proteins and AD was corroborated by the inverse variance weighted (IVW) method. The findings indicated that three circulating inflammatory proteins, namely, interleukin-18 receptor 1 [OR (CI) = 1.08 (1.05-1.11); p = 0.000001)], interleukin-8 [OR (CI) = 1.07 (1.00-1.14); p = 0.036244)], and tumor necrosis factor ligand superfamily member 14 [OR (CI) = 1.05 (1.00-1.10); p = 0.036842)], were positively correlated with AD. Additionally, six circulating inflammatory proteins were negatively correlated with AD: the T-cell surface glycoprotein CD5 [OR (CI) = 0.89 (0.84-0.95); p = 0.000191)], macrophage colony-stimulating factor 1 [OR (CI) = 0.93 (0.88-0.99); p = 0.031422)], fractalkine [OR (CI) = 0.91 (0.85-0.97); p = 0.003067)], interleukin-24 [OR (CI) = 0.91 (0.83-0.99); p = 0.031673)], signaling lymphocytic activation molecule [OR(CI) = 0.94 (0.89-1.00); p = 0.039818)], and urokinase-type plasminogen activator [OR(CI) = 0.95 (0.90-1.00); p = 0.037037)].

CONCLUSION

This study confirms the potential causal relationship between circulating inflammatory proteins and AD and provides guidance for the clinical diagnosis and treatment of AD.

Blocking the IL-4/IL-13 Axis versus the JAK/STAT Pathway in Atopic Dermatitis: How Can We Choose?

Atopic dermatitis (AD) is an immune-mediated skin disorder with a chronic-relapsing course and a multifactorial pathogenesis. In contrast to the traditional concept of AD as solely a type 2 immune-activated disease, new findings highlight the disease as highly heterogeneous, as it can be classified into variable phenotypes based on clinical/epidemiological or molecular parameters. For many years, the only therapeutic option for moderate-severe AD was traditional immunosuppressive drugs. Recently, the area of systemic therapy of AD has significantly flourished, and many new substances are now marketed, licensed, or in the last step of clinical development. Biological agents and small molecules have enriched the therapeutic armamentarium of moderate-to-severe AD, such as dupilumab, tralokinumab, lebrikizumab (monoclonal antibodies targeting the IL-4/13 pathway), abrocitinib, upadacitinib, and baricitinib (JAK inhibitors). Indeed, the AD treatment paradigm is now split into two main approaches: targeting the IL-4/13 axis or the JAK/STAT pathway. Both approaches are valid and have strong evidence of preclinical and clinical efficacy. Therefore, the choice between the two can often be difficult and represents a major challenge for dermatologists. Indeed, several important factors must be taken into account, such as the heterogeneity of AD and its classification in phenotypes, patients' comorbidities, age, and personal preferences. The aim of our review is to provide an overview of the clinical and molecular heterogeneities of AD and to explore the factors and parameters that, in clinical practice, may help inform clinical decision-making.

Senomorphic activity of a combination of niacinamide and hyaluronic acid: correlation with clinical improvement of skin aging

Intrinsic and extrinsic factors, including lifestyle and sun exposure, can contribute to cell senescence, which impairs skin homeostasis, that may in turn lead to skin aging. Senescent cells have a specific secretome, called the senescence-associated secretory phenotype (SASP) that includes MMPs, CXCLs and S100A8/9. Reducing the SASP with senotherapeutics is a promising strategy to reduce skin aging. Here we evaluated the effect of a formula containing niacinamide and hyaluronic acid, which are known to limit senescence and skin aging. We conducted three different studies. (1) Ex vivo explants treated with the formula had more collagen and glycosaminoglycan. (2) In a clinical trial with forty-four women, two months of treatment improved fine lines, wrinkles, luminosity, smoothness, homogeneity, and plumpness. (3) In a third study on thirty women, we treated one arm for two months and took skin biopsies to study gene expression. 101 mRNAs and 13 miRNAs were differentially expressed. We observed a likely senomorphic effect, as there was a decrease in many SASP genes including MMP12 and CXCL9 and a significant downregulation of autocrine signaling genes: S100A8 and S100A9. These pharmaco-clinical results are the first to demonstrate the senomorphic properties of an effective anti-aging formula in skin.

Development of a predictive algorithm for patient survival after traumatic injury using a five analyte blood panel

Severe trauma can induce systemic inflammation but also immunosuppression, which makes understanding the immune response of trauma patients critical for therapeutic development and treatment approaches. By evaluating the levels of 59 proteins in the plasma of 50 healthy volunteers and 1000 trauma patients across five trauma centers in the United States, we identified 6 novel changes in immune proteins after traumatic injury and further new variations by sex, age, trauma type, comorbidities, and developed a new equation for prediction of patient survival. Blood was collected at the time of arrival at Level 1 trauma centers and patients were stratified based on trauma level, tissues injured, and injury types. Trauma patients had significantly upregulated proteins associated with immune activation (IL-23, MIP-5), immunosuppression (IL-10) and pleiotropic cytokines (IL-29, IL-6). A high ratio of IL-29 to IL-10 was identified as a new predictor of survival in less severe patients with ROC area of 0.933. Combining machine learning with statistical modeling we developed an equation ("VIPER") that could predict survival with ROC 0.966 in less severe patients and 0.8873 for all patients from a five analyte panel (IL-6, VEGF-A, IL-21, IL-29, and IL-10). Furthermore, we also identified three increased proteins (MIF, TRAIL, IL-29) and three decreased proteins (IL-7, TPO, IL-8) that were the most important in distinguishing a trauma blood profile. Biologic sex altered phenotype with IL-8 and MIF being lower in healthy women, but higher in female trauma patients when compared to male counterparts. This work identifies new responses to injury that may influence systemic immune dysfunction, serving as targets for therapeutics and immediate clinical benefit in identifying at-risk patients.

RNA-sequencing of paired tape-strips and skin biopsies in atopic dermatitis reveals key differences

BACKGROUND

Skin tape-strips and biopsies are widely used methods for investigating the skin in atopic dermatitis (AD). Biopsies are more commonly used but can cause scarring and pain, whereas tape-strips are noninvasive but sample less tissue. The study evaluated the performance of skin tape-strips and biopsies for studying AD.

METHODS

Whole-transcriptome RNA-sequencing was performed on paired tape-strips and biopsies collected from lesional and non-lesional skin from AD patients (n = 7) and non-AD controls (n = 5). RNA yield, mapping efficiency, and differentially expressed genes (DEGs) for the two methods (tape-strip/biopsy) and presence of AD (AD/non-AD) were compared.

RESULTS

Tape-strips demonstrated a lower RNA yield (22 vs. 4596 ng) and mapping efficiency to known genes (28% vs. 93%) than biopsies. Gene-expression profiles of paired tape-strips and biopsies demonstrated a medium correlation (R2 = 0.431). Tape-strips and biopsies demonstrated systematic differences in measured expression levels of 6483 genes across both AD and non-AD samples. Tape-strips preferentially detected many itch (CCL3/CCL4/OSM) and immune-response (CXCL8/IL4/IL5/IL22) genes as well as markers of epidermal dendritic cells (CD1a/CD207), while certain cytokines (IL18/IL37), skin-barrier genes (KRT2/FLG2), and dermal fibroblasts markers (COL1A/COL3A) were preferentially detected by biopsies. Tape-strips identified more DEGs between AD and non-AD (3157 DEGs) then biopsies (44 DEGs). Tape-strips also detected higher levels of bacterial mRNA than biopsies.

CONCLUSIONS

This study concludes that tape-strips and biopsies each demonstrate respective advantages for measuring gene-expression changes in AD. Thus, the specific skin layers and genes of interest should be considered before selecting either method.

Senescent fibroblasts and innate immune cell activation might play a role in the pathogenesis of elderly atopic dermatitis

BACKGROUND

Elderly atopic dermatitis (AD) is a subtype of AD defined by age (≥ 60 years). The molecular characteristics of elderly AD remain to be clarified.

OBJECTIVE

We sought to characterize the molecular features of skin lesions and peripheral blood mononuclear cells (PBMCs) in patients with AD across different age, focusing on elderly AD.

METHODS

Skin and PBMCs samples were used for RNA sequencing. Analysis of differentially expressed genes and gene set variation analysis were performed. Immunofluorescence staining, quantitative real-time PCR (qRT-PCR), flow cytometry and transwell assay were used for validation.

RESULTS

Compared with healthy controls, the skin transcriptome of AD patients showed common signatures of AD, like barrier dysfunction and enhanced Th1/Th2/Th17 immune pathways. In PBMCs, the expression of Th1/Th2 response genes was more remarkable in adult AD, while expression of Th17-related genes was significantly higher in childhood AD. The gene modules associated with natural killer (NK) cells were downregulated in elderly AD. In skin lesions, elderly AD exhibited enrichment of macrophages, fibroblasts and senescence-associated secretory phenotype (SASP) related genes. The correlation among fibroblasts, SASP and innate immune cells were revealed by the co-localization of fibroblasts, macrophages and NK cells in the lesions across different age groups. Fibroblasts under inflammation or senescence could induce stronger chemotaxis of macrophages and NK cells.

CONCLUSION

We identified the molecular phenotypes of skin lesions and PBMCs in elderly AD individuals. Fibroblasts, innate immune cells, and SASP might play important roles in the pathogenesis of elderly AD.

Monoclonal antibodies for moderate-to-severe atopic dermatitis: a look at phase III and beyond

INTRODUCTION

The understanding of atopic dermatitis (AD) pathogenesis has rapidly expanded in recent years, catalyzing the development of new targeted monoclonal antibody treatments for AD.

AREAS COVERED

This review aims to summarize the latest clinical and molecular data about monoclonal antibodies that are in later stages of development for AD, either in Phase 3 trials or in the pharmacopoeia for up to 5 years, highlighting the biologic underpinning of each drug's mechanism of action and the potential modulation of the AD immune profile.

EXPERT OPINION

The therapeutic pipeline of AD treatments is speedily progressing, introducing the potential for a personalized medical approach in the near future. Understanding how targeting pathogenic players in AD modifies disease progression and symptomatology is key in improving therapeutic choices for patients and identifying ideal patient candidates.

Role of basal cells in nasal polyp epithelium in the pathophysiology of eosinophilic chronic rhinosinusitis (eCRS)

BACKGROUND

Basal cell hyperplasia is commonly observed in nasal polyp epithelium of eosinophilic chronic rhinosinusitis (eCRS). We examined the function and mechanisms of basal cell hyperplasia in the pathophysiology of eCRS.

METHODS

We found that normal human bronchial epithelial (NHBE) cells obtained basal cell characteristics when cultured with PneumaCult™-Ex Plus Medium. Most of the cells passaged three times expressed basal cell surface markers CD49f and CD271 by flow cytometry, and basal cell nuclear marker p63 by immunohistochemical staining. We named these NHBE cells with basal cell characteristics cultured Basal-like cells (cBC), and NHBE cells cultured with BEGM™ cultured Epithelial cells (cEC). The characteristics of cBC and cEC were examined and compared by RNA sequencing, RT-PCR, ELISA, and cell proliferation studies.

RESULTS

RNA sequencing revealed that cBC showed higher gene expression of thymic stromal lymphopoietin (TSLP), IL-8, TLR3, and TLR4, and lower expression of PAR-2 compared with cEC. The mRNA expression of TSLP, IL-8, TLR3, and TLR4 was significantly increased in cBC, and that of PAR-2 was significantly increased in cEC by RT-PCR. Poly(I:C)-induced TSLP production and LPS-induced IL-8 production were significantly increased in cBC. IL-4 and IL-13 stimulated the proliferation of cBC. Finally, the frequency of p63-positive basal cells was increased in nasal polyp epithelium of eCRS, and Ki67-positive proliferating cells were increased in p63-positive basal cells.

CONCLUSIONS

Type 2 cytokines IL-4 and IL-13 induce basal cell hyperplasia, and basal cells exacerbate type 2 inflammation by producing TSLP in nasal polyp of eCRS.

Dupilumab-associated head and neck dermatitis shows a pronounced type 22 immune signature mediated by oligoclonally expanded T cells

Dupilumab, an IL4R-blocking antibody, has shown clinical efficacy for atopic dermatitis (AD) treatment. In addition to conjunctivitis/blepharitis, the de novo appearance of head/neck dermatitis is now recognized as a distinct side effect, occurring in up to 10% of patients. Histopathological features distinct from AD suggest a drug effect, but exact underlying mechanisms remain unknown. We profiled punch biopsies from dupilumab-associated head and neck dermatitis (DAHND) by using single-cell RNA sequencing and compared data with untreated AD and healthy control skin. We show that dupilumab treatment was accompanied by normalization of IL-4/IL-13 downstream activity markers such as CCL13, CCL17, CCL18 and CCL26. By contrast, we found strong increases in type 22-associated markers (IL22, AHR) especially in oligoclonally expanded T cells, accompanied by enhanced keratinocyte activation and IL-22 receptor upregulation. Taken together, we demonstrate that dupilumab effectively dampens conventional type 2 inflammation in DAHND lesions, with concomitant hyperactivation of IL22-associated responses.

Clinical and molecular effects of oral CCR4 antagonist RPT193 in atopic dermatitis: A Phase 1 study

BACKGROUND

RPT193 is an orally administered small molecule antagonist of the human C-C motif chemokine receptor 4 (CCR4) that inhibits the migration and downstream activation of T-helper Type 2 (Th2) cells. We investigated single- and multiple-ascending doses of RPT193 in healthy subjects, and multiple doses of RPT193 in subjects with moderate-to-severe atopic dermatitis (AD).

METHODS

This was a first-in-human randomized, placebo-controlled Phase 1a/1b monotherapy study (NCT04271514) to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and CCR4 surface receptor occupancy in eligible healthy subjects and subjects with moderate-to-severe AD. Clinical efficacy and skin biomarker effects of RPT193 monotherapy were assessed as exploratory endpoints in AD subjects.

RESULTS

In healthy (n = 72) and AD subjects (n = 31), once-daily RPT193 treatment was generally well tolerated, with no serious adverse events reported and all treatment-emergent adverse events reported as mild/moderate. In AD subjects, numerically greater improvements in clinical efficacy endpoints were observed with RPT193 monotherapy versus placebo up to the end of the treatment period (Day 29), with statistically significant improvement, compared to Day 29 and placebo, observed 2 weeks after the end of treatment (Day 43) on several endpoints (p < .05). Moreover, significant changes in the transcriptional profile were seen in skin biopsies of RPT193-treated versus placebo-treated subjects at Day 29, which were also significantly correlated with improvements in clinical efficacy measures.

CONCLUSIONS

To our knowledge, this is the first clinical study with an oral CCR4 antagonist that showed clinical improvement coupled with modulation of the cutaneous transcriptomic profile in an inflammatory skin disease.

Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

An OX-Tra'Ordinary Tale: The Role of OX40 and OX40L in Atopic Dermatitis

The transmembrane glycoprotein OX40 receptor (OX40) and its ligand, OX40L, are instrumental modulators of the adaptive immune response in humans. OX40 functions as a costimulatory molecule that promotes T cell activation, differentiation, and survival through ligation with OX40L. T cells play an integral role in the pathogenesis of several inflammatory skin conditions, including atopic dermatitis (AD). In particular, T helper 2 (TH2) cells strongly contribute to AD pathogenesis via the production of cytokines associated with type 2 inflammation (e.g., IL-4, IL-5, IL-13, and IL-31) that lead to skin barrier dysfunction and pruritus. The OX40-OX40L interaction also promotes the activation and proliferation of other T helper cell populations (e.g., TH1, TH22, and TH17), and AD patients have demonstrated higher levels of OX40 expression on peripheral blood mononuclear cells than healthy controls. As such, the OX40-OX40L pathway is a potential target for AD treatment. Novel therapies targeting the OX40 pathway are currently in development, several of which have demonstrated promising safety and efficacy results in patients with moderate-to-severe AD. Herein, we review the function of OX40 and the OX40-OX40L signaling pathway, their role in AD pathogenesis, and emerging therapies targeting OX40-OX40L that may offer insights into the future of AD management.

Serum autophagy-related gene 5 level in stroke patients: correlation with CD4+ T cells and cognition impairment during a 3-year follow-up

Autophagy-related gene (ATG) 5 regulates blood lipids, chronic inflammation, CD4+ T-cell differentiation, and neuronal death and is involved in post-stroke cognitive impairment. This study aimed to explore the correlation of serum ATG5 with CD4+ T cells and cognition impairment in stroke patients. Peripheral blood was collected from 180 stroke patients for serum ATG5 and T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cell detection via enzyme-linked immunosorbent assays and flow cytometry. The Mini-Mental State Examination (MMSE) scale was completed at enrollment, year (Y)1, Y2, and Y3 in stroke patients. Serum ATG5 was also measured in 50 healthy controls (HCs). Serum ATG5 was elevated in stroke patients compared to HCs (P<0.001) and was positively correlated to Th2 cells (P=0.022), Th17 cells (P<0.001), and Th17/Treg ratio (P<0.001) in stroke patients but not correlated with Th1 cells, Th1/Th2 ratio, or Treg cells (all P>0.050). Serum ATG5 (P=0.037), Th1 cells (P=0.022), Th17 cells (P=0.002), and Th17/Treg ratio (P=0.018) were elevated in stroke patients with MMSE score-identified cognition impairment vs those without cognition impairment, whereas Th2 cells, Th1/Th2 ratio, and Treg cells were not different between them (all P>0.050). Importantly, serum ATG5 was negatively linked with MMSE score at enrollment (P=0.004), Y1 (P=0.002), Y2 (P=0.014), and Y3 (P=0.001); moreover, it was positively related to 2-year (P=0.024) and 3-year (P=0.012) MMSE score decline in stroke patients. Serum ATG5 was positively correlated with Th2 and Th17 cells and estimated cognitive function decline in stroke patients.

The epidermal lipid-microbiome loop and immunity: Important players in atopic dermatitis

BACKGROUND

The promotion of epidermal barrier dysfunction is attributed to abnormalities in the lipid-microbiome positive feedback loop which significantly influences the imbalance of the epithelial immune microenvironment (EIME) in atopic dermatitis (AD). This imbalance encompasses impaired lamellar membrane integrity, heightened exposure to epidermal pathogens, and the regulation of innate and adaptive immunity. The lipid-microbiome loop is substantially influenced by intense adaptive immunity which is triggered by abnormal loop activity and affects the loop's integrity through the induction of atypical lipid composition and responses to dysregulated epidermal microbes. Immune responses participate in lipid abnormalities within the EIME by downregulating barrier gene expression and are further cascade-amplified by microbial dysregulation which is instigated by barrier impairment.

AIM OF REVIEW

This review examines the relationship between abnormal lipid composition, microbiome disturbances, and immune responses in AD while progressively substantiating the crosstalk mechanism among these factors. Based on this analysis, the "lipid-microbiome" positive feedback loop, regulated by immune responses, is proposed.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review delves into the impact of adaptive immune responses that regulate the EIME, driving AD, and investigates potential mechanisms by which lipid supplementation and probiotics may alleviate AD through the up-regulation of the epidermal barrier and modulation of immune signaling. This exploration offers support for targeting the EIME to attenuate AD.

Sclerotic-Type Cutaneous Chronic Graft-Versus-Host Disease Exhibits Activation of T Helper 1 and OX40 Cytokines

Sclerotic-type cutaneous chronic graft-versus-host disease is a severe complication of allogeneic hematopoietic stem cell transplantation, with profound morbidity. A dearth of effective, targeted treatment options necessitates further investigation into the molecular mechanisms underlying this T-cell-mediated disease. In this study, we compared the transcriptome in skin biopsies from pediatric and young adult (aged <25 years) patients with sclerotic-type cutaneous chronic graft-versus-host disease (n = 7) with that in demographically matched healthy controls (n = 8) and patients with atopic dermatitis (n = 10) using RNA sequencing with RT-PCR and immunohistochemistry validation. Differential expression was defined as fold change > 1.5 and false discovery rate < 0.05. Sclerotic-type cutaneous chronic graft-versus-host disease exhibited strong and significant T helper (Th)1 skewing through key related cytokines and chemokines (CXCL9/10/11, IFNG/IFN-γ, STAT1/signal transducer and activator of transcription 1). Several markers related to the TSLP-OX40 axis were significantly upregulated relative to those in both controls and lesional atopic dermatitis, including TNFSF4/OX40L, TSLP, and IL33, as well as fibroinflammatory signatures characterized in a prior study in systemic sclerosis. Gene set variation analysis reflected marker-level findings, showing the greatest enrichment of the Th1 and fibroinflammatory pathways, with no global activation identified in Th2 or Th17/Th22. Cell-type deconvolution revealed a significant representation of macrophages and vascular endothelial cells. Sclerotic-type cutaneous chronic graft-versus-host disease in young patients may therefore be characterized by strong Th1-related upregulation with a unique TSLP-OX40 signature, suggesting new therapeutic avenues for this devastating disease.

Unraveling Atopic Dermatitis: Insights into Pathophysiology, Therapeutic Advances, and Future Perspectives

Atopic dermatitis (AD) is an inflammatory skin condition that frequently develops before the onset of allergic rhinitis or asthma. More than 10% of children are affected by this serious skin condition, which is painful for the sufferers. Recent research has connected the environment, genetics, the skin barrier, drugs, psychological factors, and the immune system to the onset and severity of AD. The causes and consequences of AD and its cellular and molecular origins are reviewed in this paper. The exploration of interleukins and their influence on the immunological pathway in AD has been facilitated by using relevant biomarkers in clinical trials. This approach enables the identification of novel therapeutic modalities, fostering the potential for targeted translational research within the realm of personalized medicine. This review focuses on AD's pathophysiology and the ever-changing therapeutic landscape. Beyond the plethora of biologic medications in various stages of approval or development, a range of non-biologic targeted therapies, specifically small molecules, have emerged. These include Janus kinase (JAK) inhibitors like Baricitinib, Upadacitinib, and Abrocitinib, thus expanding the spectrum of therapeutic options. This review also addresses the latest clinical efficacy data and elucidates the scientific rationale behind each targeted treatment for atopic dermatitis.

Diversity of atopic dermatitis and selection of immune targets

Atopic dermatitis (AD) is a heterogeneous immune-mediated skin disorder affecting people of all ages and ethnicities. Despite the development of targeted therapeutics such as biologics and Janus kinase inhibitors, attaining complete clinical efficacy remains difficult. This therapeutic challenge may be attributed to the complex pathogenesis of AD. Although the TH2 axis has been extensively studied, recent advancements have started to reveal the involvement of additional immune pathways including TH1, TH17, and TH22. Understanding the interplay of these immune axes may contribute to a more personalized therapeutic approach based on patients' molecular profile, with the prospect of improving clinical outcome. This review will discuss studies exploring the molecular profile of AD in both skin and blood across age, ethnicity/race, disease chronicity, IgE levels, filaggrin mutation status, and AD association with other atopic conditions. Moreover, it will explore the potential of personalized treatment strategies based on a patient's distinct immune signature.

Atopic dermatitis phenotypes based on cluster analysis of the Danish Skin Cohort

BACKGROUND

Despite previous attempts to classify atopic dermatitis (AD) into subtypes (e.g. extrinsic vs. intrinsic), there is a need to better understand specific phenotypes in adulthood.

OBJECTIVES

To identify, using machine learning (ML), adult AD phenotypes.

METHODS

We used unsupervised cluster analysis to identify AD phenotypes by analysing different responses to predetermined variables (age of disease onset, severity, itch and skin pain intensity, flare frequency, anatomical location, presence and/or severity of current comorbidities) in adults with AD from the Danish Skin Cohort.

RESULTS

The unsupervised cluster analysis resulted in five clusters where AD severity most clearly differed. We classified them as 'mild', 'mild-to-moderate', 'moderate', 'severe' and 'very severe'. The severity of multiple predetermined patient-reported outcomes was positively associated with AD, including an increased number of flare-ups and increased flare-up duration and disease severity. However, an increased severity of rhinitis and mental health burden was also found for the mild-to-moderate phenotype.

CONCLUSIONS

ML confirmed the use of disease severity for the categorization of phenotypes, and our cluster analysis provided novel detailed information about how flare patterns and duration are associated with AD disease severity.

Cutaneous basophil infiltration in atopic dermatitis is associated with abundant epidermal infiltration of helper T cells: A preliminary retrospective study

Atopic dermatitis (AD) is a heterogenous inflammatory skin disorder. Our previous study revealed that basophil infiltration in skin is observed in approximately 60% of AD cases. However, the clinical and histological characteristics of AD associated with basophil infiltration remain unclear. We examined basophil infiltration by immunohistochemical staining of 38 specimens from 34 patients who underwent skin biopsies to diagnose AD from April 2016 to September 2021 at Tokyo Medical and Dental University Hospital. The patients/specimens were divided into two groups, 17 patients/21 specimens associated with little or no basophil infiltration (basophil-low group) and 17 patients/17 specimens associated with marked basophil infiltration (basophil-high group). The clinical characteristics of the patients (age, sex, complications, blood biomarkers, skin symptoms, and treatment) and histological features of the specimens were compared between the groups. Basophil-high patients were significantly younger than basophil-low patients. Blood basophil counts were higher in basophil-high patients than in basophil-low patients. CD4+ T-cell infiltration was more marked in basophil-high specimens than in basophil-low specimens. CD4+ T cells infiltrated into the dermis as well as into the epidermis only in the basophil-high specimens. Thus, basophil-high AD can be characterized by skin lesions associated with abundant helper T-cell infiltration in younger patients.

Intrapatient comparison of atopic dermatitis skin transcriptome shows differences between tape-strips and biopsies

BACKGROUND

Our knowledge of etiopathogenesis of atopic dermatitis (AD) is largely derived from skin biopsies, which are associated with pain, scarring and infection. In contrast, tape-stripping is a minimally invasive, nonscarring technique to collect skin samples.

METHODS

To construct a global AD skin transcriptomic profile comparing tape-strips to whole-skin biopsies, we performed RNA-seq on tape-strips and biopsies taken from the lesional skin of 20 moderate-to-severe AD patients and the skin of 20 controls. Differentially expressed genes (DEGs) were defined by fold-change (FCH) ≥2.0 and false discovery rate <0.05.

RESULTS

We detected 4104 (2513 Up; 1591 Down) and 1273 (546 Up; 727 Down) DEGs in AD versus controls, in tape-strips and biopsies, respectively. Although both techniques captured dysregulation of key immune genes, tape-strips showed higher FCHs for innate immunity (IL-1B, IL-8), dendritic cell (ITGAX/CD11C, FCER1A), Th2 (IL-13, CCL17, TNFRSF4/OX40), and Th17 (CCL20, CXCL1) products, while biopsies showed higher upregulation of Th22 associated genes (IL-22, S100As) and dermal cytokines (IFN-γ, CCL26). Itch-related genes (IL-31, TRPV3) were preferentially captured by tape-strips. Epidermal barrier abnormalities were detected in both techniques, with terminal differentiation defects (FLG2, PSORS1C2) better represented by tape-strips and epidermal hyperplasia changes (KRT16, MKI67) better detected by biopsies.

CONCLUSIONS

Tape-strips and biopsies capture overlapping but distinct features of the AD molecular signature, suggesting their respective utility for monitoring specific AD-related immune, itch, and barrier abnormalities in clinical trials and longitudinal studies.

Treat-to-target in dermatology: A scoping review and International Eczema Council survey on the approach in atopic dermatitis

Treat-to-target (T2T) is a pragmatic therapeutic strategy being gradually introduced into dermatology after adoption in several other clinical areas. Atopic dermatitis (AD), one of the most common inflammatory skin diseases, may also benefit from this structured and practical therapeutic approach. We aimed to evaluate existing data regarding the T2T approach in dermatology, with a specific focus on AD, as well as the views of International Eczema Council (IEC) members on the potential application of a T2T approach to AD management. To do so, we systematically searched for peer-reviewed publications on the T2T approach for any skin disease in the PubMed and Scopus databases up to February 2022 and conducted a survey among IEC members regarding various components to potentially include in a T2T approach in AD. We identified 21 relevant T2T-related reports in dermatology, of which 14 were related to psoriasis, five to AD, one for juvenile dermatomyositis and one for urticaria. In the IEC member survey, respondents proposed treatable traits (with itch, disease severity and sleep problems getting the highest scores), relevant comorbidities (with asthma being selected most commonly, followed by anxiety and depression in adults), recommended specialists that should define the approach in AD (dermatologists, allergists and primary care physicians were most commonly selected in adults), and applicable assessment tools (both physician- and patient-reported), in both adult and paediatric patients, for potential future utilization of the T2T approach in AD. In conclusion, while the T2T approach may become a useful tool to simplify therapeutic goals and AD management, its foundation in AD is only starting to build. A multidisciplinary approach, including a wide range of stakeholders, including patients, is needed to further define the essential components needed to utilize T2T in AD.

Atopic Dermatitis in the Elderly Population

Atopic dermatitis is a common inflammatory disease with a chronic and relapsing course. Although considered a childhood disease, it is now evident that atopic dermatitis is also common in adulthood and in the elderly population. Atopic dermatitis typically manifests with bilateral and symmetrical eczematous lesions on the face, trunk and skin folds. Itch is invariably present and may be very severe, markedly  affecting daily life and sleep. In older adults, atopic dermatitis may have a high level of impact on quality of life, frequently burdening an already complex comorbid situation. The full assessment of disease burden (localizations, itch severity, sleep alterations, impact on quality of life, disease history, comorbidities) is crucial to identify the most appropriate treatment. In many cases, moderate-to-severe atopic dermatitis in the elderly population can be successfully and safely treated with biological agents inhibiting the interleukin-4/-13 pathway, whereas the use of Janus kinase inhibitors may pose concerns about the safety profile.

Prediction of disease severity using serum biomarkers in patients with mild-moderate Atopic Dermatitis: A pilot study

Atopic dermatitis (AD) is an inflammatory skin condition that relies largely on subjective evaluation of clinical signs and symptoms for diagnosis and severity assessment. Using multivariate data, we attempted to construct prediction models that can diagnose the disease and assess its severity. We combined data from 28 mild-moderate AD patients and 20 healthy controls (HC) to create random forest models for classification (AD vs. HC) and regression analysis to predict symptom severities. The classification model outperformed the random permutation model significantly (area under the curve: 0.85 ± 0.10 vs. 0.50 ± 0.15; balanced accuracy: 0.81 ± 0.15 vs. 0.50 ± 0.15). Correlation analysis revealed a significant positive correlation between measured and predicted total SCORing Atopic Dermatitis score (SCORAD; r = 0.43), objective SCORAD (r = 0.53), eczema area and severity index scores (r = 0.58, each p < 0.001), but not between measured and predicted itch ratings (r = 0.21, p = 0.18). We developed and tested multivariate prediction models and identified important features using a variety of serum biomarkers, implying that discovering the deep-branching relationships between clinical measurements and serum measurements in mild-moderate AD patients may be possible using a multivariate machine learning method. We also suggest future methods for utilizing machine learning algorithms to enhance drug target selection, diagnosis, prognosis, and customized treatment in AD.

Epithelial Barrier Theory: The Role of Exposome, Microbiome, and Barrier Function in Allergic Diseases

Allergic diseases are a major public health problem with increasing prevalence. These immune-mediated diseases are characterized by defective epithelial barriers, which are explained by the epithelial barrier theory and continuously emerging evidence. Environmental exposures (exposome) including global warming, changes and loss of biodiversity, pollution, pathogens, allergens and mites, laundry and dishwasher detergents, surfactants, shampoos, body cleaners and household cleaners, microplastics, nanoparticles, toothpaste, enzymes and emulsifiers in processed foods, and dietary habits are responsible for the mucosal and skin barrier disruption. Exposure to barrier-damaging agents causes epithelial cell injury and barrier damage, colonization of opportunistic pathogens, loss of commensal bacteria, decreased microbiota diversity, bacterial translocation, allergic sensitization, and inflammation in the periepithelial area. Here, we review scientific evidence on the environmental components that impact epithelial barriers and microbiome composition and their influence on asthma and allergic diseases. We also discuss the historical overview of allergic diseases and the evolution of the hygiene hypothesis with theoretical evidence.

Efficacy and Safety of Dupilumab in Older Patients (Aged 80 Years and Above) with Atopic Dermatitis: A Prospective Study

BACKGROUND

Atopic dermatitis presents unique challenges in the older population owing to age-related changes in skin barrier function and immune regulation. However, there is limited evidence on the efficacy and safety of dupilumab, an anti-interleukin-4Rα monoclonal antibody, in patients with atopic dermatitis aged 80 years and above.

OBJECTIVE

We aimed to assess the clinical efficacy and safety of dupilumab treatment in patients with atopic dermatitis aged 80 years and above.

METHODS

Twenty-eight older patients received dupilumab and were evaluated based on several clinical parameters, including the Eczema Area and Severity Index (EASI), Numeric Rating Scale (NRS), Dermatology Life Quality Index (DELI), and AD Control Tool (ACT). Safety assessments and monitoring of concomitant medication use were conducted.

RESULTS

Twenty-six patients completed 16 weeks of treatment, 13 completed 28 weeks, and two completed more than 36 weeks. Dupilumab treatment resulted in a significant improvement in atopic dermatitis symptoms after 16 weeks as demonstrated by reduced EASI, NRS, DLQI, and ADCT scores. Dupilumab had no significant impact on underlying diseases or medication use. No common adverse reactions, such as conjunctivitis and erythema of the face and neck, were identified. Among the 26 patients receiving dupilumab treatment during the COVID-19 pandemic, 17 remained uninfected or experienced milder COVID-19 symptoms than experienced in the general population.

CONCLUSIONS

Dupilumab treatment showed significant efficacy in improving atopic dermatitis symptoms in patients aged 80 years and above with a high level of safety. Larger long-term clinical trials are needed to validate these results and provide further evidence for the use of dupilumab in older patients with atopic dermatitis.

Comparative Study of Hematological Parameters and Biomarkers of Immunity and Inflammation in Patients with Psoriasis and Atopic Dermatitis

Background and Objectives: There are no studies regarding comparative analysis of hematological parameters in patients with psoriasis (PsO) and atopic dermatitis (AD), whereas studies examining serum biomarkers of immunity and inflammation in these entities are scarce and contradictory. We aimed to compare such parameters in patients with PsO and AD. Materials and Methods: Patients with PsO (n = 40) and AD (n = 40) were consecutively included in this cross-sectional study. Hematological parameters and biomarkers of immunity and inflammation (interferon-gamma (IFN-γ), interleukine (IL)-22 and C-reactive protein (CRP)) were determined. Results: While the mean corpuscular volume (MCV) was higher in the PsO group vs. the AD group (p < 0.05), there was no difference in the other examined parameters between groups. A higher neutrophil-to-lymphocyte ratio (NLR) was found in patients with AD > 50 years vs. patients with PsO of similar age (p < 0.05). Higher IL-22 levels were found in patients with AD < 50 years vs. patients with PsO of similar age (p < 0.05). Lower IL-22 levels were found in patients with AD > 50 years vs. patients with AD < 50 years (p < 0.05). Patients with PsO and with comorbidities had lower platelets (PLT), plateletcrit (PCT) and platelet-to-lymphocyte ratio (PLR), whereas lymphocytes, red cell distribution width-to-PLT ratio (RPR) and mean platelet volume/PLT ratio (MPR) were higher vs. PsO patients without comorbidities. Patients with AD and with comorbidities had lower PCT and PLR, whereas RPR was higher vs. AD patients without comorbidities. Conclusions: A higher pro-inflammatory state (i.e., higher NLR and IL-22) was found in AD vs. PsO in age-specific groups. A higher pro-inflammatory state (i.e., as reflected by platelet indexes) was found in both diseases with comorbidities.

Peripheral blood mononuclear cell- transcriptome signatures of atopic dermatitis and prediction for the efficacy of dupilumab

BACKGROUND

Few studies have explored transcriptome of the peripheral blood mononuclear cells (PBMCs) of atopic dermatitis (AD). Parameters for prediction of the efficacy of dupilumab in AD remain obscure.

OBJECTIVE

To explore transcriptome signature of the PBMCs from Chinese AD patients and the usage in predication for the efficacy of dupilumab.

METHODS

A total of 56 moderate-to-severe adult AD patients were enrolled and followed up for 16 week-dupilumab treatment. PBMCs samples were collected at baseline and 16 weeks after dupilumab treatment. Thirty-five patients were subjected to RNA-sequencing. Weighted gene co-expression network analysis (WGCNA) was used to find genes for prediction of dupilumab efficacy, which was validated in the rest 21 AD patients. Another 30 healthy individuals were enrolled and subjected to RNA-sequencing as healthy controls.

RESULTS

Upregulation of the T helper (Th) 2/Th22 pathway, Th17 antimicrobial genes, and natural T-regulatory cell abundance in the PBMCs of AD cases was observed, whereas TGF-β signaling and NK-cell signaling were decreased. Dupilumab treatment reversed the increase in the expression of Th2 cytokine receptors. WGCNA identified two immune-related modules that were correlated significantly with the efficacy of dupilumab. Hub gene MAP2K3 and UBE2L3 of these two modules demonstrated potential predictive ability for efficacy in the RNA-sequencing group by Spearman correlation, ROC analysis, and regression analysis, which was further validated in additional 21 AD cases.

CONCLUSION

We firstly revealed the molecular phenotype of PBMCs in Chinese patients with AD, and uncovered two molecules that might be useful for prediction of the efficacy of dupilumab.

Association of Inflammatory Indicators and Clinical Signs and Itch in Atopic Dermatitis Patients Treated with Simiao Pill Combined with Halomethasone Cream

Background

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by symptoms such as itchiness, scaling, and erythema. Previous studies have suggested that inflammatory indicators obtained from peripheral blood cell count can serve as markers for atopic dermatitis pruritus and severity. The objective of this study was to investigate whether these indicators are associated with treatment efficacy in AD patients who received a combination of halomethasone cream and Simiao pill (SMP).

Methods

131 adult patients diagnosed with AD between January 2020 to August 2022 and treated with topical halometasone ointment combined with oral Simiao pill for a month were recruited and clinical dates of patients were collected. Inflammatory indicators included Eosinophil-to-lymphocyte ratio (ELR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), serum leukotriene B4 (LTB4), and thymic stromal lymphopoietin (TSLP) and clinical indexes for assessing eczema area and severity index (EASI) and peak pruritus-numerical rating scale (PP-NRS). Relationship of baseline and changes of these Inflammatory indicators and that of clinical indexes were analyzed.

Results

ELR, NLR, LTB4, and TSLP levels have positive association with EASI before treatment, and baseline ELR and LTB4 levels have positive relationship with PP-NRS. ELR, NLR, LTB4, and TSLP showed a significant decrease at week 2 and the low levels were maintained until week 8 after treatment, while no significant changes were observed in levels of MLR and PLR. There was a significant correlation between the decrease of ELR and the decreases of EASI and PP-NRS at weeks 2, 4 and 8 of the treatment.

Conclusion

ELR may serve as an effective and convenient indicator in assessing the disease severity and efficacy of SMP therapy for AD.

Disease modification in inflammatory skin disorders: opportunities and challenges

Progress in understanding of the mechanisms underlying chronic inflammatory skin disorders, such as atopic dermatitis and psoriasis vulgaris, has led to new treatment options with the primary goal of alleviating symptoms. In addition, this knowledge has the potential to inform on new strategies aimed at inducing deep and therapy-free remission, that is, disease modification, potentially impacting on associated comorbidities. However, to reach this goal, key areas require further exploration, including the definitions of disease modification and disease activity index, further understanding of disease mechanisms and systemic spillover effects, potential windows of opportunity, biomarkers for patient stratification and successful intervention, as well as appropriate study design. This Perspective article assesses the opportunities and challenges in the discovery and development of disease-modifying therapies for chronic inflammatory skin disorders.

Phenotypic and Endotypic Determinants of Atopic Dermatitis Severity From the Atopic Dermatitis Research Network (ADRN) Registry

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a highly variable clinical phenotype.

OBJECTIVE

This study aimed to identify historical and clinical features and biomarkers associated with AD severity.

METHODS

A US registry of extensively phenotyped AD participants (aged 0.73-80 years) were enrolled at 9 academic centers. Information on family and personal medical history, examination, skin swabs (culture), and serum biomarkers was collected to evaluate their association with AD severity.

RESULTS

Participants with AD (N = 2862) whose disease was categorized as mild (11.6%), moderate (58.0%), or severe (30.4%) based on Rajka-Langeland scoring were enrolled. The trend test, when adjusting for gender, race, and age, demonstrated that severity was strongly (P ≤ .04) associated with a personal/family history of allergic disorders, history of alopecia, exposure to passive smoke, ocular herpes infection, skin bacterial and viral infections, and history of arrhythmia. Features observed more frequently (P ≤ .002), as a function of severity, included skin infections (impetigo, human papillomavirus, and molluscum contagiosum virus), Staphylococcus aureus colonization, excoriations, hyperlinear palms, ichthyosis, blepharitis, conjunctivitis, ectropion, and wheezing. Serum IgE, allergen and food (≤6 years) Phadiatop, and eosinophilia were strongly linked to severity (P < .001).

CONCLUSIONS

In a diverse US AD population, severity was associated with a history of atopic disorders, skin and extracutaneous bacterial and viral infections (by history and physical examination), higher IgE, eosinophilia and allergen sensitization, atopic skin manifestations (ie, excoriation, hyperlinear palms, and ichthyosis), and atopic ocular features (ie, blepharitis, conjunctivitis, and ectropion) as well as asthma findings (ie, wheezing). Data from our prospective registry significantly advance our understanding of AD phenotypes and endotypes, which is critical to achieve optimal management.

Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood

BACKGROUND

Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls.

METHODS

We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, Zürich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; ≥2 to 6; ≥7 to 11; ≥12 to 18); adult-onset ≥18 years: 23.6% (subsets: ≥18 to 40; ≥41 to 60; ≥61) and 167 controls (91 atopic, 76 non-atopic)).

RESULTS

We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controlsnon-atopic , aOR = 4.03 [1.20-13.45] vs. controlsatopic ). Conjunctivitis showed a negative association versus controlsatopic (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controlsatopic . Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset ≥61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters.

CONCLUSIONS

The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors.

IL17A mRNA Staining Distinguishes Palmoplantar Psoriasis from Hyperkeratotic Palmoplantar Eczema in Diagnostic Skin Biopsies

Acral dermatoses, including hyperkeratotic palmoplantar eczema (HPE), palmoplantar psoriasis (PP), and mycosis fungoides palmaris et plantaris (MFPP), can be challenging to diagnose clinically and histopathologically. In this setting, cytokine biomarkers may be able to help provide diagnostic clarity. Therefore, we evaluated IL-17A, IFN-γ, and IL-13 expression in PP, HPE, and MFPP and compared their expression profiles with nonacral sites. We used biopsy specimens from the Yale Dermatopathology database, selecting cases of HPE (n = 12), PP (n = 8), MFPP (n = 8), normal acral skin (n = 9), nonacral eczema (n = 10), and nonacral psoriasis (n = 10) with classic clinical and histopathologic features. IL17A mRNA expression by RNA in situ hybridization differentiated PP (median score 63.1 [interquartile range 9.4-104.1]) from HPE (0.8 [0-6.0]; P = 0.003), MFPP (0.6 [0-2.6]; P = 0.003), and normal acral skin (0 [0-0]; P < 0.001). Unexpectedly, both PP and HPE showed co-expression of IFNG and IL13 mRNA. In contrast, nonacral psoriasis and eczema showed divergent patterns of IFNG and IL13 mRNA expression. Taken together, we show that IL17A mRNA expression may be a useful biomarker of PP, and we further show that acral dermatoses exhibit distinct immunology compared to nonacral sites, with implications for clinical management.

Proteomic characterization of atopic dermatitis blood from infancy to adulthood

BACKGROUND

Patients with atopic dermatitis (AD) have systemic biomarker dysregulation that differs by age group; however, the proteomic characteristics of these age-based changes are unknown.

OBJECTIVE

To profile blood proteins of patients with AD across different age groups versus age-appropriate controls.

METHODS

Using the Olink high-throughput proteomic platform, we profiled 375 serum proteins of 20 infants (age, 0-5 years), 39 children (age, 6-11 years), 21 adolescents (age, 12-17 years), and 20 adults (age, ≥18 years) with moderate-to-severe AD and 83 age-appropriate controls.

RESULTS

Each group presented a distinct systemic proteomic signature. Th2-related proteins were increased in infant AD and further intensified with age through adolescence and adulthood (interleukin 4/CCL13/CCL17). In contrast, Th1 axis down-regulation was detected in infants with AD and gradually reversed to increased Th1 products (interferon γ/CXCL9/CXCL10/CCL2) in patients with AD from childhood to adulthood. Despite their short disease duration, infants already had evidence of systemic inflammation, with significant upregulation of innate immunity (interleukin 17C/ interleukin-1RN), T-cell activation/migration (CCL19), Th2 (CCL13/CCL17), and Th17 (PI3) proteins. Adults with AD present unique upregulation of cardiovascular proteins related to coagulation and diabetes.

LIMITATIONS

Cross-sectional observational study with a single time point.

CONCLUSION

Systemic immune signatures of AD are age-specific beyond the shared Th2 immune activation. These data advocate for precision medicine approaches based on age-specific AD profiles.

Immunosenescence and Skin: A State of Art of Its Etiopathogenetic Role and Crucial Watershed for Systemic Implications

Immunosenescence is a complex multifactorial phenomenon consisting of wide-ranging remodeling of the immune system during the life span, resulting in an age-related qualitative-quantitative decline of immune cells and cytokines. A growing body of evidence in the international literature is highlighting the etiopathogenetic role of skin immunosenescence in the onset of various dermatologic conditions. Skin immunosenescence also serves as an interesting watershed for the onset of system-wide conditions in the context of allergic inflammation. Moreover, in recent years, an increasingly emerging and fascinating etiopathogenetic parallelism has been observed between some mechanisms of immunosenescence, both at cutaneous and systemic sites. This would help to explain the occurrence of apparently unconnected comorbidities. Throughout our review, we aim to shed light on emerging immunosenescent mechanisms shared between dermatologic disorders and other organ-specific diseases in the context of a more extensive discussion on the etiopathogenetic role of skin immunosenescence. A promising future perspective would be to focus on better understanding the mutual influence between skin and host immunity, as well as the influence of high inter-individual variability on immunosenescence/inflammaging. This can lead to a more comprehensive "immunobiographic" definition of each individual.

The translational revolution in atopic dermatitis: the paradigm shift from pathogenesis to treatment

Atopic dermatitis (AD) is the most common inflammatory skin disease, and it is considered a complex and heterogeneous condition. Different phenotypes of AD, defined according to the patient age at onset, race, and ethnic background; disease duration; and other disease characteristics, have been recently described, underlying the need for a personalized treatment approach. Recent advancements in understanding AD pathogenesis resulted in a real translational revolution and led to the exponential expansion of the therapeutic pipeline. The study of biomarkers in clinical studies of emerging treatments is helping clarify the role of each cytokine and immune pathway in AD and will allow addressing the unique immune fingerprints of each AD subset. Personalized medicine will be the ultimate goal of this targeted translational research. In this review, we discuss the changes in the concepts of both the pathogenesis of and treatment approach to AD, highlight the scientific rationale behind each targeted treatment and report the most recent clinical efficacy data.

The Eosinophil-to-Lymphocyte Ratio Acts as an Indicator for Improvement of Clinical Signs and Itch by Upadacitinib Treatment in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with severe itch. The eosinophil-to-lymphocyte ratio (ELR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) are reported to reflect itch or the severity of AD. We examined if these parameters may act as indicators for therapeutic effects of the Janus kinase 1 inhibitor upadacitinib for patients with AD in real-world clinical practice. Between August 2021 and September 2023, 65 Japanese patients (aged ≥ 12 years) with moderate to severe AD were treated with 15 mg/day of oral upadacitinib, plus twice daily topical corticosteroids. Before treatment, the baseline ELR, NLR, MLR, and PLR levels positively correlated with the eczema area and severity index (EASI), while the baseline NLR and PLR levels positively correlated with the peak pruritus-numerical rating scale (PP-NRS). After upadacitinib treatment, ELR and NLR remarkably decreased at week 4 and the reduced levels were maintained until week 24, in parallel with EASI and PP-NRS, while MLR and PLR transiently reduced at week 4, but returned to baseline levels after week 12. The percent reduction of ELR significantly correlated with the percent reductions of EASI and PP-NRS at weeks 4, 12, and 24 of upadacitinib treatment. ELR may act as an indicator for the improvement of clinical signs and itch by upadacitinib treatment in AD.

Efficacy and Safety of Dupilumab Maintained in Adults ≥ 60 Years of Age with Moderate-to-Severe Atopic Dermatitis: Analysis of Pooled Data from Four Randomized Clinical Trials

BACKGROUND

Adults aged ≥ 60 years are often underrepresented in atopic dermatitis (AD) clinical trials; age-related comorbidities may impact treatment efficacy and safety.

OBJECTIVE

The aim was to report dupilumab efficacy and safety in patients aged ≥ 60 years with moderate-to-severe AD.

METHODS

Data were pooled from four randomized, placebo-controlled dupilumab trials of patients with moderate-to-severe AD (LIBERTY AD SOLO 1 and 2, LIBERTY AD CAFÉ, and LIBERTY AD CHRONOS) and stratified by age (< 60 [N = 2261] and ≥ 60 [N = 183] years). Patients received dupilumab 300 mg every week (qw) or every 2 weeks (q2w), or placebo with/without topical corticosteroids. Post hoc efficacy at week 16 was examined using broad categorical and continuous assessments of skin lesions, symptoms, biomarkers, and quality of life. Safety was also assessed.

RESULTS

In the ≥ 60-year-old group at week 16, a greater proportion of dupilumab-treated patients achieved an Investigator's Global Assessment score of 0/1 (q2w: 44.4%; qw: 39.7%) and 75% improvement in Eczema Area and Severity Index (63.0%; 61.6%) versus placebo (7.1% and 14.3%, respectively; P < 0.0001). Type 2 inflammation biomarkers (immunoglobulin E and thymus and activation-regulated chemokine) were also significantly reduced in dupilumab- versus placebo-treated patients (P < 0.01). Results were similar in the < 60-year-old group. The exposure-adjusted incidences of adverse events in dupilumab-treated patients were generally similar to those receiving placebo, with numerically fewer treatment-emergent adverse events in the dupilumab-treated ≥ 60-year-old group versus placebo.

LIMITATIONS

There were fewer patients in the ≥ 60-year-old group; post hoc analyses.

CONCLUSION

Dupilumab improved AD signs and symptoms in patients aged ≥ 60 years; results were comparable to those in patients aged < 60 years. Safety was consistent with the known dupilumab safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02277743, NCT02277769, NCT02755649, NCT02260986. Does dupilumab benefit adults aged 60 years and older with moderate-to-severe atopic dermatitis?(MP4 20,787 KB).

Biomarkers in atopic dermatitis

Atopic dermatitis (AD) is a complex and highly heterogeneous inflammatory skin disease. Given the highly heterogeneous character of AD, it is unlikely that every patient will respond equally to a particular treatment. The recent introduction of novel targeted therapies for AD has driven the need for patient stratification based on immunologic biomarkers. We have reviewed the use of different types of biomarkers as potential tools in the movement toward personalized medicine in AD, comprising different ways of endotyping patients with AD based on immunologic profiles and predictive biomarkers. The application of biomarkers will result in better characterization and stratification of patients and allow better comparison of current and new treatments. The ultimate goal will be to switch from the current generalized "one-drug-fits-all" management to more personalized "patient endotype-specific" management.

Oral Janus kinase inhibitors for atopic dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin conditions. The pathogenesis of AD involves skin barrier disruption and immune activation of T-helper (T_H)2 and T_H22 and varying degrees of T_H1 and T_H17 activation in various patient subtypes. Although AD is mainly driven by T_H2, the molecular and clinical heterogeneity of AD underscores the need for more efficacious treatments that target multiple immune axes. Janus kinase (JAK) inhibitors are novel therapeutics that broadly block many AD-related proinflammatory cytokines (interleukin [IL]-4, IL-5, IL-13, IL-31, thymic stromal lymphopoietin, interferon gamma, IL-12, IL-23, IL-17) across different immune pathways. Oral JAK inhibitors have been found to be efficacious in AD, with 2 (abrocitinib and upadacitinib) recently gaining US Food and Drug Administration approval and several others under investigation in clinical trials with promising results. These systemic agents have surpassed conventional thresholds of treatment response, with many patients achieving complete or almost complete skin clearance, and provide a fast-acting alternative therapy for patients who are not responsive to biologics or other conventional therapies. However, systemic JAK inhibitors come with health concerns, requiring additional long-term clinical trials to characterize their safety profile in patients with AD. This review summarizes the current literature on the safety and efficacy of oral JAK inhibitors in AD and discusses future directions for research.

The evolving landscape of biologic therapies for atopic dermatitis: Present and future perspective

Atopic dermatitis (AD) is one of the most common, chronic inflammatory skin diseases with a significant physical, emotional and socioeconomic burden. In recent years the understanding of AD pathogenesis has expanded from the Th2-centred perspective, with the recognition of the involvement of other immune axes. In different AD endotypes, influenced by environment, genetics and race, transcriptomic profiles have identified differing contributions of multiple immune axes such as, Th17, Th22 and Th1. The enriched pathogenic model of AD has catalysed the development of numerous biologic therapies targeting a range of key molecules implicated in disease progression. Currently, dupilumab and tralokinumab, which both target the Th2 pathway, are the only approved biologic therapies for AD in the United States and Europe. New biologic therapies in development, however, target different Th2-pathway molecules along with cytokines in other immune axes, including Th17 and Th22, offering promise for varied treatments for this heterogeneous disease. As the biologic pipeline advances, the integration into clinical practice and approval of these experimental biologics may provide more effective, tailored therapeutic solutions and illuminate on the pathologic processes of AD across a broader, more diverse patient population.

Shedding light on key pharmacological knowledge and strategies for pediatric atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory disease affecting over 20% of the pediatric population, with 85% of cases presenting before the age of five. Recently, therapeutic options in pediatric patients have evolved rapidly, following extensive development in adult treatments.

AREAS COVERED

This review will encompass relevant molecular drivers, along with an overlook on treatment modalities in pediatric AD, as well as a summary of pipeline treatments in clinical trials for pediatric patients from PubMed, Google Scholar, and Clinicaltrials.gov up to July 2022. Topical corticosteroids are the mainstay for AD flares in adults and children. Topical approved agents in pediatric AD are calcineurin inhibitors, crisaborolecrisaborole, and ruxolitinib. Dupilumab is the only FDA approved biologic for patients with AD from six months of age. A Janus kinase inhibitor, upadacitinib, is a systemic treatment approved for pediatric AD patients (age >12 years). Systemic immunosuppressants used in pediatric AD include methotrexate, azathioprine, cyclosporinecyclosporine, and mycophenolate mofetil.

EXPERT OPINION

Data regarding disease prevention are conflicting, however, an abundance of research has transpired regarding amelioration of symptoms and induction of disease clearance by targeting numerous pathological mechanisms. Understanding the pediatric AD phenotype will further advance the field and the development of improved therapeutics.

Multiplex Proteomic Evaluation in Inborn Errors with Deregulated IgE Response

(1) Background: Atopic dermatitis constitutes one of the most common inflammatory skin manifestations of the pediatric population. The onset of many inborn errors occurs early in life with an AD-like picture associated with a deregulated IgE response. The availability of proteomic tests for the simultaneous evaluation of hundreds of molecules allows for more precise diagnosis in these cases. (2) Methods: Comparative genomic hybridization microarray (Array-CGH) analysis and specific IgE evaluation by using allergenic microarray (ISAC) and microarray (ALEX2) systems were performed. (3) Results: Proteomic investigations that use multiplex methods have proven to be extremely useful to diagnose the sensitization profile in inborn errors with deregulated IgE synthesis. Four patients with rare diseases, such as recessive X-linked ichthyosis (RXLI, OMIM 308100), Comel-Netherton syndrome (NS, OMIM256500), monosomy 1p36 syndrome (OMIM: 607872), and a microduplication of Xp11.4 associated with extremely high levels of IgE: 7.710 kU/L, 5.300 kU/L, 1.826 kU/L, and 10.430 kU/L, respectively, were evaluated by micro- and macroarray multiplex methods. Polyreactivity to both environmental and food allergens was observed in all cases, including the first described case of association of X-chromosome microduplication and HIE. (4) Conclusions: Extensive use of proteomic diagnostics should be included among the procedures to be implemented in inborn errors with hyper-IgE.

Delayed type hypersensitivity reactions to various allergens may differently model inflammatory skin diseases

BACKGROUND

Treatment of inflammatory skin diseases, including atopic dermatitis (AD) and psoriasis, is undergoing transformative changes, highlighting the need to develop experimental models of skin inflammation in humans to predict treatment responses.

METHODS

We topically or intradermally administered four common sensitizers (dust mite (DM), diphencyprone (DPCP), nickel (Ni), and purified protein derivative (PPD)) to the backs of 40 healthy patients and the skin hypersensitivity response was biopsied and evaluated using immunohistochemistry, RNA-seq, and RT-PCR.

RESULTS

All agents induced strong increases in cellular infiltrates (T-cells and dendritic cells) as compared to untreated skin (p < .05), with variable T helper polarization. Overall, DPCP induced the strongest immune responses across all pathways, including innate immunity (IL-1α, IL-8), Th1 (IFNγ, CXCL10), Th2 (IL-5, CCL11), and Th17 (CAMP/LL37) products, as well as the highest regulatory tone (FOXP3, IL-34, IL-37) (FDR <0.01). Nickel induced Th17 (IL-17A), Th1 (CXCL10) and Th2 (IL-4R) immune responses to a lesser extent than DPCP (p < .05). PPD induced predominantly Th1 (IFNγ, CXCL10, STAT1) and Th17 inflammation (IL-17A) (p < .05). DM induced modulation of Th2 (IL-13, CCL17, CCL18), Th22 (IL-22), and Th17/Th22 (S100A7/9/12) pathways (p < .05). Barrier defects that characterize both AD and psoriasis were best modeled by DPCP and Ni, followed by PPD, including downregulation of terminal differentiation (FLG, FLG2, LOR, LCEs), tight junction (CLDN1/CLDN8), and lipid metabolism (FA2H, FABP7)-related markers.

CONCLUSION

Our data imply that DPCP induced the strongest immune response across all pathways, and barrier defects characteristic of AD and psoriasis.

CCL13 and human diseases

CCL13/MCP-4 belongs to the CC chemokine family, which induces chemotaxis in many immune cells. Despite extensive research into its function in numerous disorders, a thorough analysis of CCL13 is not yet accessible. The role of CCL13 in human disorders and existing CCL13-focused therapies are outlined in this study. The function of CCL13 in rheumatic diseases, skin conditions, and cancer is comparatively well-established, and some studies also suggest that it may be involved in ocular disorders, orthopedic conditions, nasal polyps, and obesity. We also give an overview of research that found very little evidence of CCL13 in HIV, nephritis, and multiple sclerosis. Even though CCL13-mediated inflammation is frequently linked to disease pathogenesis, it's fascinating to note that in some conditions, like primary biliary cholangitis (PBC) and suicide, it might even act as a preventative measure.

Childhood blood eosinophils and symptoms of allergic disorders: a cross-sectional study in Southern China

PURPOSE

The relationship between childhood blood eosinophils and subtypes of allergic diseases remains understudied. This study aimed to examine the associations between childhood blood eosinophils and subtypes of asthma, rhinitis and dermatitis, as well as the modifying effect of age.

METHODS

We obtained concurrent blood cell counts and serum Immunoglobulin E (IgE) test results in 5026 children (0-13, years) from First Affiliated Hospital of Guangzhou Medical University from 2014 to 2019. Generalized additive models with multivariable adjustments were utilized to model the exposure-response relationship between eosinophils and allergic symptoms. The robustness of the association was assessed in two age categories (<6, 6-13 years).

RESULTS

The association of eosinophils with allergic asthma/rhinitis was positively nonlinear, with a plateau at levels of Q₄ (≥0.51, 10⁹/L). Conversely, exposure-response curves between eosinophils and the risk of non-allergic asthma and rhinitis were negatively linear, and especially, became statistically significant when levels of eosinophils were larger than Q₃ (≥0.30, 10⁹/L). Compared with their counterparts, school-aged children (6-13, years) with a higher level of blood eosinophils (≥0.35, 10⁹/L) were more likely to suffer from allergic asthma [relative excess risk due to interaction (RERI), 2.51; 95% CI, 1.24-3.78], allergic rhinitis (RERI, 2.79; 95% CI, 1.14-4.45) but not allergic dermatitis (RERI not significant).

CONCLUSION

Higher eosinophil counts were associated with the increased risk of allergic subtype symptoms and the decreased risk of non-allergic subtypes in children. Moreover, the associations between eosinophils and allergic asthma/rhinitis were accentuated in the school-aged child. These findings may contribute to providing novel insights for clinical administration relevance of allergic-related symptoms.Key messages:There was a positively nonlinear association between childhood eosinophils and allergic asthma/rhinitis.Age modified the associations between eosinophils and allergy-related outcomes. The associations of eosinophil with allergic asthma/rhinitis accentuated in the school-aged child (6-13, years).

Atopic dermatitis across the life course

Atopic dermatitis, the most common chronic inflammatory skin disease, can occur at any age, and patterns of disease activity vary over time. Both prevalence and incidence are highest in infancy and early childhood, followed by a second peak in older adulthood. Birth cohort studies from European countries following children through adolescence have identified subgroups of patients with early-onset persistent disease, early-onset resolving disease, and later-onset disease. Parental history of atopy and genetic factors are among the most consistent predictors of more persistent disease. Studies have begun to examine whether molecular markers differ by age group, although longitudinal data are lacking. Breastfeeding, probiotics and skin-directed therapies such as emollients have been investigated as potential preventive measures, but randomized trials have not found consistent long-term benefit. Future research should focus on patterns of disease activity beyond early adulthood and the role of treatments on long-term disease activity.